1. Field of the Invention
The present invention generally relates to improvements in adjustable wrenches and more specifically a lock for an adjustable wrench to lock the adjustable jaw of the wrench in adjusted position. The lock includes a slide mounted on the wrench handl adjacent the head of the wrench for longitudinal slidable and guided movement with a thumb receiving member at the end of the slide remote from the wrench head and an arcuately curved recess on the inner surface of the slide engaging with the rotatable worm wheel used to adjust the adjustable jaw of the wrench thereby retaining the worm wheel and adjustable jaw in adjusted position by frictional engagement between the slide and worm wheel. The slide includes a longitudinal slot receiving a pin which slidably anchors the slide to the wrench handle adjacent the wrench head with the end of the slide remote from the wrench head including a depending tapering projection to engage and be guided by longitudinal edge ridges or flanges normally provided on the handle of an adjustable wrench thereby maintaining the slide in longitudinal alignment with the wrench handle for movement toward and away from the rotatable worm wheel used to adjust the adjustable jaw of the wrench.
2. Description of the Prior Art
Adjustable wrenches of various types are known and on the market. One of the most popular adjustable wrenches being marketed is a crescent wrench which includes an adjustable jaw having a rack gear thereon which is engaged by a rotatable worm gear which has a peripheral rib provided with serrations which are exposed to opposite sides of the wrench head to enable the worm wheel to be rotated for adjusting the adjustable jaw. When using the wrench, the adjustable jaw frequently moves from its adjusted position which can cause the wrench to slip off of the nut or bolt head with which it is engaged. This frequently results in injury due to rapid acceleration of the wrench handle when the wrench releases from the nut or bolt head with the knuckles of the hand gripping the wrench handle sometimes coming into contact with stationary objects resulting in injury to the knuckles. This phenomena is generally referred to as "knuckle busting" and adjustable end wrenches are well known for their "knuckle busting" characteristics. In view of this ongoing problem, efforts have been made to prevent accidental rotation of the worm wheel which results in maladjustment of the adjustable jaw. The following U.S. patent relate to efforts to solve the problem of the adjustable jaw of an adjustable wrench moving during normal use of the wrench.
1,321,777 PA1 1,749,002 PA1 2,309,529 PA1 2,780,124 PA1 4.548,104
None of the above patents disclose the specific novel features of the lock for an adjustable wrench incorporated into this invention.